Induction unit



INDUCTION UNIT 3 Sheets-Sheet 1 Filed March 26, 1962 I N VEN TORS RONALD W. BROWN WA LTER EA RHA RT ATTORNEYS Aug. 3, 1965 R. w. BROWN ETALINDUCTION UNIT 5 Sheets-Sheet 2 Filed March 26, 1962 INVENTORS RONALD W.BROWN WALTER EARHA RT AT TORNEYS 1965 R. w. BROWN ETAL 3,198,246

INDUCTION UNIT Filed March 26, 1962 3 Sheets-Sheet 5 FIGS BY F/G.8 FIG.9wmam United States Patent 3,193,246 TNDEUETEQN "UNTT Ronald W. BrownWalter Earhart, La Crosse, Wis assignors to The Trans Comp-any, LaCrosse, Wis. Filed Mar. 26, W62, Ser. No. lldzdl il ll Elaiin. (til.1165-35) This invention relates generally to air conditioning units andmore specifically to induction type air conditioning units which employa source of conditioned primary air to induce a secondary stream of roomair through a heat exchange coil within the unit.

It is an object of the invention to provide an induction unit whichemploys a bypass for secondary air to control the temperature of thespace being conditioned.

A second object of the invention is to provide an induction unit whichemploys a bypass for secondary air which is controlled by a dampermember using the primary air as a source of motive power.

Another object of the invention is to provide an induction unit whichemploys the primary air as a source of power for the control as well asthe motive force for a bypass damper.

A fourth object of the invention is to provide an induction unit whichemploys a new and novel nozzle structure which is readily assembled andinexpensive to manufacture.

These and other objects and advantages of the invention will more fullyappear from the following description to be read in connection with theaccompanying drawings in which:

FIGURE 1 is a front elevational view of the unit of this invention withportions of the cabinet broken away to disclose the interiorconstruction;

FIGURE 2 is a cross-sectional view taken on line 2-2 of FIGURE 1;

FIGURE 3 is a schematic representation of the bypass damper control;

FIGURE 4 is a blown up view showing in detail the bypass damper and theattachment of the control bladder;

FTGURE 5 is a top view of the primary air regulator;

FIGURE 6 is a view taken on line 6ti of FIGURE 5;

FTGURE 7 is an end view of the regulator shown in FIGURE 6;

FIGURE 8 is an elevational view of the nozzle plate employed in the unitshown in FIGURES 1 and 2;

FIGURE 9 is a side view of the inducing nozzles with a portion of thenozzle member shown in cross-section; and

FIGURE 10 is a rear view of the nozzles shown in FIGURE 9.

Referring now to FTGURES 1 and 2, numeral 10 denotes a heat exchangeunit of the induction type. Preferably induction unit ltl is mounted ona wall 12 a predetermined distance above the floor line 1 to define akickspace to for the introduction of room air into the unit. This air iscommonly referred to as secondary air.

In operation, primary conditioned air having a total pressure on theorder of /2" to 5 water gauge is introduced into chamber 13 of theprimary air plenum chamber 2t through inlet conduit 22. A regulator 24to be described in detail hereafter regulates the flow of primary airfrom chamber 13 to chamber 25'. A triangular sound attenuator 26 islocated in the primary air stream from the regulator 24 to attenuate thenoise level of the primary air and to provide a restricted inlet portion23 in order to obtain proper pressure conditions at the nozzle strips36. Acoustical insulation 31 is connected to the walls of primary airplenum chamber ice and triangular sound attenuator 26 to dampen thesound inherent in the primary air stream.

Primary air ejected from the nozzle strips 3b into the inducing chamber32 defined by the plenum chamber Ztl and the baflle member 33 inducessecondary air from the kickspace either through the heat exchanger 34 orthrough the bypass passage 36 depending on the location of the bypassdamper 33. The secondary air induced mixes in the inducing chamber 32with the primary air from the nozzle strip 3% and is discharged into theconditioned area through discharge grille d0 in the top panel 42 of theheat exchanger unit ltl.

Regulator 24 shown in detail in FIGURES 5-7 consists basically of alower plate 54 with louver portions 4-6 formed downwardly therefrom andan upper plate 48 slidably supported on the low plate with the louverportions 5t formed downwardly therefrom cooperating with louver portion46 to provide a series of smooth edged adjustable orifices 47 for thepassage of primary air from chamber 18 to chamber 25.

To control the sliding movement of upper plate 48, a control shaft 52 isrotatably secured in bracket 54 welded or otherwise secured to flanges56 on lower plate 44 and is keyed to U-shaped bracket 5'8. U-shapedbracket 58 is telescoped over stud member 6t rigidly secured to upperplate 48. It should be noted that slot shaped aperture 62 in U-shapedbracket 58 is considerably larger in diameter than stud member whichprojects therethrough.

In operation, control shaft 52 is rotated clockwise or counterclockwiseby any suitable means to close or open orifices 47 respectivelydepending on the particular requirements of the area being conditioned.The slot shaped aperture 62 allows U-shaped bracket 5?; to swing in anarc and provide linear motion of the upper plate 48 to control theamount of opening of the orifices 57 by sliding the upper plate 48. Feltbead strips 59 are employed to allow the upper plate to be readilymoved.

After the primary air has entered the primary air chamber through theregulator 24, it passes through the nozzle strips 3h shown in detail inFTGURES 8-10. Nozzle strips may be constructed of any suitable materialsuch as metal or plastic; however, we prefer to make them of plastic.The nozzle strips 3t? consist of a plurality of nozzles d4 arranged in arow in the vertical direction. The longitudinal axes of the nozzles 64makes an angle of 30 with respect to the nozzle strip 3b. This angle maybe as small as 20 but it should not be greater than The cross-sectionalarea of each nozzle 64 decreases continually from the entrance of thenozzle to the throat or discharge face. The entrance to the nozzles 64have smoothly rounded surfaces. For primary air pressures of about 1.5inches water gauge we prefer to use nozzles having throat diameters inthe range of .09 to .2 inch.

Nozzle frame mounting member an is suitably m0unted to the primary airchamber 25 forming the front side or" the chamber. Nozzle frame as hasnozzle slots es formed therein to accommodate nozzle strips 3d. Thenumber of nozzle strips and nozzle slots being dependent on therequirements of the space being conditioned.

To assemble the nozzle strips 36 to the nozzle frame 6'6, nozzle strip36 is placed so that tabs 69 on the back of nozzle strip 349 align withoblong slots or notches 7G in the nozzle frame. The tabs ea are thenplaced in the slots 76) and the nozzle strip is slid downwardly innozzle slot 68 until projection '72 engages the upper edge '74 of nozzleslot 68 to lock the nozzle strip lid in place. It should be noted that aspace '76 is left between the tabs 69 and the front portion '78 of thenozzle trip to allow the tabs 69 to slide on the back of nozzle framewhile the front portion '78 slides on the front of nozzle frame 66.

Looking now in detail at FIGURES 24, the operation of the bypass damperwill be discussed. in the position shown in solid lines in FIGURE 2, thebypass damper 38 is abuttinga sealing member dti and is blocking thebypass passage 36 so that all the secondary air is being induced throughthe heat exchanger 34 to be conditioned.

in induction systems which employ a source of primary air, the primaryair is normally supplied continuously which means that some system ofcontrol must be incorporated to maintain the proper temperature in thespace being conditioned. This condition prevails on both the heating andcooling cycles. In the preferred embodiment shown, the bypass damper isemployed to maintain the proper temperature in the conditioned space. This is accomplished by controlling the amount of air induced in the heatexchanger and at the same time inducing room air through the bypasspassage 3d to mix with the primary air and the secondary air passingover the heat exchanger. Bypass damper 38 modulates from the positionshown in solid lines where all the secondary air is induced through theheat exchanger 34 to the position shown in dotted lines where all thesecondary air is being induced through the bypass passage 36. Atintermediate positions between these two extremes, a mixture of bypassair and conditioned air will be induced into the inducing chamber 32 tobe mixed with the primary air.

In the lower portion of the induction unit It? the bypass passage isdefined by the bypass damper 33 and the front panel 32.

The bypass damper consists of three basic components. These componentsare the bladder containing member 34 connected to the heat exchanger 34in any suitable manner, the bypass damper blade 33, and a strip ofspring steel 86 or suitable substitute attached at its lower end 88 tothe bladder containing member 34 and to the bypass damper blade 38 atits upper end by suitable means such as screws 92.

As indicated in FIGURE 4, the inflation and deflation of the flexiblebladder member 94 controls the position of the bypass damper 33. At thefully inflated position indicated in dotted lines in FIGURE 2, thebypass passage 36 is open and the air passage through the heat exchangemember 34 is closed. Conversely, when the bladder member 94- is deflatedthe damper 3% assumes the position shown in solid lines closing off thebypass passage 3i; and allowing all the secondary air to be inducedthrough the heat exchanger 34.

The inflation and deflation of the bladder member is preferablyaccomplished by the use of a source of air under pressure. in thepreferred form of the invention, the source of air employed is theprimary air delivered to the unit. Obviously, a separate air sourcecould be employed but the use of the primary air already present in thesystem eliminates the use of additional equipment and provides a unitwhich can be considered self contained and does not need additionalwiring or pneumatic lines for control.

Cooling Looking now at FIGURE 3, the control will be explained.Basically, the control consists of a pressure reducing valve 96, atemperature reversing valve 9%, and a pneumatic controller lltiti. Thecontrol as shown is in the position when cold heat exchange fluid isbeing supplied to the heat exchanger 34 via conduit ltd. and thethermostatic bulb Mid is indicating a demand for cooling in theconditioned space.

Reversing valve 93 is providing communication between conduit Kidd andbleed line llti'd since thermostatic element llltl is sensing a coldfluid in conduit M32 and thereby being in its contracted positionallowing spring 112 to force valve ball 114 against valve port 116 tocut off communication between conduit 1% and bleed line 113.

Control air at the proper pressure is being supplied to conduit lit-=6through pressure reducing valve Eh: and restricter Mu from the primaryair plenum chamber 2% or other suitable position. Flexible bladder is inits deflated position allowing all the secondary air to be inducedthrough the heat exchanger 34 since bellows member 122 is in itsexpanded position indicating a need for cooling in the conditioned spaceand thus causing flapper member 124 to be pivoted away from bleed line1% allowing the control air from conduit 1% to bleed to the atmosphererather than build up pressure in the conduit 126 and flexible bladdermember 96.

As the temperature in the conditioned space approaches the requiredtemperature, the bellows 122 will contract allowing the spring 128 topivot flapper member 124 tow. 5.5 the bleed conduit and restricting theflow of control therefrom. T he pressure in conduit 12d and flexiblebladder 94 will increase causing the bladder member 94 to pivot thebypass damper blade towards the primary air plenum chamber 2%} therebyopening the bypass passagv and restricting the conditioned air passage.The amount of opening and closing of the bypass air passage beingdependent on the required conditions of the conditioned space as set onthe pneumatic controller fifitl. When the temperature in the conditionedspace is completely satisfied, bleed line A58 will be totally restrictedallowing flexible bladder 94 to be expanded to the dotted line positionthus allowing all the induced air to pass through the bypass passage as.

Heating Assuming now that heating fluid is being supplied to heatexchanger 34 through conduit 7. 92, the thermostatic element 11% of thereversing valve 98 will be expanded forcing valve ball 114 upwardagainst the bias of spring 112. closing off bleed line res and openingvalve port 116 to provide communication between conduit 1% and bleedline 118. This reverses the action of pneumatic controller 109.

When the temperature in the space being conditioned is low indicating aneed for heat, bellows 122 will be contracted allowing spring 123 topivot flapper arm 12d away from bleed line 113 and thereby bleeding thecontrol air to the atmosphere. Flexible bladder member 94 will then bein the deflated position causing damper blade id to be in the solid lineposition closing off the bypass passage 36 and allowing all thesecondary air to be induced through the heat exchanger 34.

As the temperature of the conditioned space approaches the requiredtemperature, bellows 12 will expand and pivot flapper member 124 towardsbleed line 118 to r strict the flow or" control air therefrom. Flexiblebladder member will then start to expand, since the pressure in conduit1% and the bladder is increasing, causing the damper blade 33 to bepivoted towards the primary air plenum chamber As before, the bypasspassage will be opened and the conditioned air passage will berestricted. When the temperature in the conditioned space is satisfied,the flexible bladder will be fully expanded to the dotted line positionclosing off completely the flow of secondary air through the heatexchanger 34 and allowing all the secondary air to be induced throughthe bypass passage 36.

The above described induction unit is very compact and does not requireany external wiring or piping other than the primary air conduit. Thisinduct on unit is readily assembled, more inexpensive to manufacture,and provides a compact unit which lessens the amount of worlr necessaryto place it in operation.

Although we have described in detail the preferred embodiments of ourinvention, we contemplate that many changes may be made withoutdeparting from the scope or spirit of our invention and We desire to belimited only by the claim.

enemas We claim:

An air conditioning unit adapted to be mounted against a wall, in aconditioned space a predetermined distance above the floor comprising: asubstantially rectangular casing, a recirculated air opening in thebottom of said casing, a discharge opening in the top of said casing,said casing having a front panel, a heat exchanger mounted in the lowerportion of said casing and inclined upwardly and rearwardly at an angleto said front panel, one corner of said heat exchanger being adjacentthe rear of said casing, means forming a passage extending from belowsaid heat exchanger between said front panel and said heat exchanger tobypass recirculated air, a primary air plenum chamber supported in theupper portion of said unit, means for supplying air under pressure tosaid primary air plenum chamber, regulating means dividing said primaryair plenum chamber into a first chamber and a second chamber, saidsupply air being delivered to said first chamber, nozzle means connectedto said second chamber, damper means pivotally supported between i saidbypass passage and said heat exchanger, and control means operablyassociated with said damper means to control the pivoting of said dampermeans in response to load conditions to regulate the proportions ofrecirculated air induced through the heat exchanger and the bypasspassage by said nozzle means.

References Cited by the Examiner UNITED STATES PATENTS Bodmer 137-62533Ewald 165-40 Ewald 236-38 Stacey 98-40 Matner et a1.

Mercier et al. 137-62533 Broberg 98-40 Peple 98-41 Pfarrer 251-61McDonald 236-13 Newton 165-123 X Bottorf et al 165-123 Ashley et al.98-40 Millman.

Ashley et al. 98-38 X Ashley et al 165-26 Great Britain.

ALDEN D. STEWART, Examiner.

